“We love the romantic pretense of a homogenous, melting-pot America. It makes us feel good, gives us a sense of nobility and brings closure to our well-documented history of discriminating against one another in every way that it is possible for humans to discriminate — race, class, ethnicity, religion, gender, geography, sexual preference.

We’ve codified this politesse in various advertising campaigns, many of which follow a set formula — a woman here, man there, black person there, Asian here, Latino there.

“Look,” the advertisements seem to say. “We’re being fair. We’ve included everybody. Buy from us.”

But a new approach to marketing says that the seemingly inclusive ads are nonsense, poppycock, almost as offensive as the advertising campaigns of old that portrayed all wholesome families as white and all breadwinners as white men.

“It’s what we call Multicultural Marketing 101,” said Monique Tapie, communications director for Global Advertising Strategies, a New York-based firm specializing in ethnic marketing and other highly targeted marketing campaigns.

“Multicultural 101 assumes that all Asians are alike, that all African Americans are alike, that all Spanish-speaking people are alike, that we are all alike, which means that we’re all mainstream,” Tapie said, with “mainstream” still considered to be white.

Consider automotive advertisements on television that feature racially mixed occupants in a car or truck. The driver usually is white and male. When gender changes, the driver is white and female. Black or other vehicle occupants of color usually sit in the front passenger’s seat, as in current advertisements for the Mitsubishi Lancer sports car. Or they sit in the rear. But they very seldom sit behind the wheel, in charge of the car.

To many blacks, especially to black men who want to be seen as leaders, those advertisements are turnoffs. Why? Because the ads place them in a symbolically subordinate, dependent position — not good for people who have spent much of their lives trying to overcome the economic and psychological ravages of past discrimination.

Multicultural Marketing 101 does not understand such nuances, just as it does not understand the animus of many middle-class and upper-income blacks against advertising campaigns that seem to portray all black people as hip-hop artists or sports figures. It seems to think that all Asians are from Japan, China or Korea, and all Spanish-speaking people are from Mexico, and all Mexicans are alike.

Global Advertising employs what it says is a more sophisticated strategy, which relies on in-depth studies of cultural groups, the differences within those groups and how those differences might yield lucrative market segments.

Consider the South Asian population in the United States, which Tapie’s company said “has developed into a sophisticated market that combines culturally unique and mainstream buying habits.”

South Asians, primarily from India, tend to come to the United States with high levels of training in science and mathematics and computer literacy, according to about 800 interviews Global Advertising conducted in 2006. Their education and technical skills tend to place them in the upper-income brackets. They are substantially more comfortable getting their information online than they are through traditional mass media outlets, such as television and newspapers, Tapie said.

That means a car company or any other retailer wanting to attract South Asian buyers must have a strong online presence, according to the Global Advertising survey. “The group’s extensive use of online media for news and information . . . provides new opportunities for marketing professionals who can recognize product trends that run the gamut from financial services to telecommunications usage,” the survey said.

But the move to targeted ethnic marketing also has a downside, particularly for old-line retailers long wedded to traditional mass-media marketing campaigns.

Consider the plight of the domestic automobile industry in attracting buyers who are recent immigrants to the United States. “People tend to stick with who they know,” Tapie said.

In India, those people know Toyota, Honda and Mercedes-Benz much better than they know General Motors, Ford and Chrysler.

So, when they come to the United States, they already are predisposed to buy a Mercedes before a Cadillac, or a Honda before a Chevrolet, she said.

Converting those buyers to domestic brands is difficult, mostly because domestic car companies still rely on the buckshot approach to advertising — sending out generic “buy me” television messages using Japanese Americans or Korean Americans to demonstrate “diversity,” Tapie said.

Technically savvy buyers, such as those in the nation’s South Asian population, now estimated to be 5 million people, “simply Tivo those ads” — simply bypass them electronically — and turn to the Internet, Tapie said.

Ethnic marketing is not a matter of cynically exploiting racial, ethnic, class or other differences for profit, Tapie said, defending her company’s marketing approach. “It’s simply a recognition that differences exist, that America is composed of many cultures and that if you plan to sell to those cultures, you’d better try to do a better job of understanding them.””